Also, here's another tip: Don't put fresh hyd. fluid in an floor jack that's been around for awhile. The floor jack seals or "O" rings probably have small, even microscopic, cracks in them (from dirt, dust, small metal particles). This defeats the "O" rings BUNA coating, which makes the rubber impermeable. The trouble arises when the new oil, which is loaded with lanolin, is added. The lanolin is to keep the rubber & synthetic parts soft and pliable. Over time the lanolin will evaporate and become a non-issue. But when the new oil is added and the lanolin gets into the small cracks it turns the "O" ring to the consistency of chewing gum (eventual failure). You'd be better off putting a small amount of a pure oil in the reservoir. Even a small amount of vegetable or mineral oil will do. With that being said, most floor jacks sold today are sealed and not made to be taken apart so you can't change the seals or "O" rings. If you are fortunate to have, or find one, that can be taken apart you are very lucky. Keep it or buy it, they are worth their weight in gold to a mechanic.
